Field of the Invention
The invention relates to a snap-action drive for a switching device having an energy store, a swinging movable part of a gear mechanism and a securing device for the movable part.
A snap-action drive is known, for example, from published, non-prosecuted German patent application DE 10 2014 203 902 A1. The snap-action drive in the application is configured for a switching device, wherein the snap-action drive has an energy store. The energy store interacts with a swinging movable part of a gear mechanism, wherein a securing device is provided for preventing undesired movements of the movable part. The securing device is configured here in such a way that recesses into which a bolt element of the securing element can be moved are formed in the movable part. As a result, a movement of the movable part in the application can be blocked. Retraction and extension of the bolt element are controlled as a function of a change in position of the energy store in the application.
A disadvantage with such a solution is that time intervals occur in which the movable part is not secured. However, such unsecured time intervals constitute a risk for the reliable functioning of the snap-action drive. Although a play-free configuration of the mechanism can result in a reduction in the unsecured time intervals, this measure becomes ineffective as the wear increases, and the risk of undefined movements of the movable part therefore increases.